Freshwater Wetlands: Ecology, Rehabilitation and 2 Management Chapter 2.1 — Ecology of urban freshwater wetlands • 53

2.1 Ecology of urban freshwater wetlands

Dr Liza Miller Watershed Ecology 6/42 – 46 Waters Road, Cremore NSW Sydney 2090

Abstract Wetlands in urban environments are subject to an array of anthropogenic disturbances leading to wetland degradation or a state of environmental change from what a wetland might be in a natural setting. This is largely because developed landscapes affect wetland condition through impacts emanating from surrounding uplands as well as the immediate area. In particular, urban landscapes influence nutrient and pollutant inputs through water deposition leading to issues such as eutrophication. Nonetheless, urban wetlands are often valued for their amenity as well as their environmental attributes. Recreation activities, including kayaking, sailing, and bird watching, contribute to wetland amenity. The environmental values of a wetland and human activities in and around a wetland pose a challenge for wetland managers. That is, natural processes, such as eutrophication, have to be managed to ensure that recreational activities can be maintained but human health is not adversely affected. As well, opportunities for native flora and fauna need consideration in order to promote wetland values for their recreational use. This chapter introduces wetland ecology and examines the impact of urban activities on wetland condition. Three Australian case studies are examined; the Dandenong wetland (Victoria), Lake (Australian Capital Territory), and the wetlands (Australian Capital Territory). All three wetlands are constructed, and with the exception of the Dandenong Wetland, multiple uses need to be managed to promote their condition and manage human activities in and around the wetlands. Chapter 2.1 — Ecology of urban freshwater wetlands • 54

Introduction the characteristics of the local landscape, including the river reaches, the values of a wetland may vary. Wetlands in the Catchment For instance, a delta-based wetland, through which River catchments are areas that funnel water into a river runs, will fulfil more of a water – filter/flow flowing streams (Coenraads and Koivula 2007). At moderator function, while water bodies cut off higher altitudes, there might be thousands of these from an active river channel fulfil more of a role as small streams that join to form larger streams that sheltered habitats or refugia (Kleeman et al. 2008). eventually meet the dominant river (Coenraads and Wetlands Defined Koivula 2007). Rivers are dynamic systems. Their drainage patterns, channel, meander, alluvial fans Irrespective of the wetland type, a wetland is and delta constantly change; sometimes quite typically an area of land covered by shallow water. dramatically after flood events (Coenraads and A more formal definition is provided in chapter 2.2, Koivula 2007). as adopted by Ramsar Convention. Wetlands can be natural or artificial, permanent or temporary. Wetlands are usually associated with flowing The water in them can be still or flowing, and fresh, rivers and streams (Coenraads and Koivula brackish, or salty (Melbourne Water n.d.). Wetland 2007). They occur in areas of a catchment where areas are defined according to their depth, degree the water table is at or above the land surface and timing of inundation and often the degree of for prolonged periods, providing waterlogged brackishness. Functionally, wetlands can be divided conditions for aquatic biota. Wetland character, into three zones: or the assemblages of flora and fauna that influence wetland patterns and processes, is largely • Inlet zone. The inlet zone is where a river determined by its location in the landscape. That or creek meets the wetland. This zone slows is, whether they are associated with montane or water flows and enables larger sediment headwater environments, or floodplain or coastal particles carried in the water to settle and riverine environments. sink. Aquatic plants may also grow in the edges of this area and as such, are able to withstand The shape and extent of a wetland depends fast water flows. on the underlying topography, geology and its location in the landscape over a larger drainage • Macrophyte zone. The macrophyte zone basin. Montane wetlands are typically associated comprises of plants that are wholly or partly with headwater streams in mountainous regions inundated. Here plants trap nutrients, heavy (Kleeman et al. 2008). For instance, the Snowy metals, suspended solids and organic matter. Mountains has numerous small montane wetlands • Open water zone. The open water zone where snowmelt drains into low-lying areas, provides opportunities for finer particles to keeping them constantly saturated (Kleeman et settle out of the water column and sunlight al. 2008). These areas are important as they tend to kill pathogenic bacteria. Due to sunlight to distribute run-off over prolonged periods and and high nutrient levels, algal growth occurs support unique communities of plants and animals from time to time in this zone. Algae trap (Kleeman et al. 2008). the dissolved nutrients, which allows them Riverine wetlands typically form in lower reaches to either enter the food chain or settle to the of a river catchment where a larger river is bottom of the pond. characterised by extensive meandering channels that twist and turn through a broad alluvial Wetland Ecology floodplain. Many loops of these meanders have Hydrology been cut to form oxbow lakes or billabongs Wetland hydrology is dealt with in greater details and these, together with extensive marshes, in chapters 2.2 and 3.2 in this eBook. For the benefit form remnants of a river’s past active channel of this chapter a brief overview of hydrology is (Coenraads and Koivula 2007). Usually a billabong provided here. or oxbow remains isolated from its neighbouring river (Kleeman et al. 2008), but during floods the Many wetlands fulfil an important role in the billabong may form part of an active river channel landscape. Some wetland functions are (after (Kleeman et al. 2008). Toward the lower reaches of (Kleeman et al. 2008); a catchment, floodplain and coastal wetlands begin • Reduce or moderate river flow and enable to dominate lentic environments. Depending on sediments to settle; Chapter 2.1 — Ecology of urban freshwater wetlands • 55

• Trap sediment and nutrients; Wetland Health or Condition • Provide habitat for fish, birds, vegetation and Wetlands are among the most impacted and invertebrates; degraded of all ecological systems. A global • Provide refugia for migratory birdlife; and overview indicates that massive losses of wetlands have occurred worldwide and that the majority • Provide a resource area for recreation and of the remaining wetlands are degraded, or cultural events. under threat of degradation (Finlayson 2000). The A key factor influencing wetland condition and health or condition of wetlands and associated extent is the hydrology or water regimes that, in vegetation communities can be negatively turn, influence wetland functions or ecology as impacted by changes in salinity, sedimentation, mentioned previously. Wetland ecosystem health pollution, removal and destruction of wetland (including the vegetation) is generally dependent habitat, and altered wetting regimes. These on natural water regimes that may be highly threatening processes can impact on the fauna variable. The wetland water regimes include the directly, through direct toxic effects, or indirectly, following features (Boulton and Brock 1999a): for example, through the loss of suitable breeding, sheltering and feeding sites and isolation of species’ • Timing of water presence. For seasonal populations due to lack of water connectivity; wetlands within-year patterns are important particularly between floodplain wetlands and while among-year patterns and variability in their adjacent river system. These impacts and timing are relevant to temporary wetlands. threats can result in declines of aquatic biodiversity • Frequency of wetland filling and drying occurs. from these systems. Activities causing such These regimes can range from zero (permanent impacts are believed to be large-scale clearing of waters) to frequent filling and drying in shallow native vegetation, use of fertilisers and erosion wetlands many times a year. of agricultural land, and regulation of rivers for water supply and irrigation (Department of • Periods of inundation. Inundation can Conservation and Environment, and Office of the vary from days to years and vary within and Environment 1992). Other activities that potentially among wetlands. Rates of rise and fall may threaten wetlands are infilling, over-grazing by also be important. livestock, introduced species, littering and pollution • The area of inundation and depth of water (Department of Conservation and Environment, and in a wetland. Office of the Environment 1992). • Wetland variability. That is, the degree to Many naturally occurring wetlands in Australia are which these above features change at a range modified, through human-induced disturbance of time scales such as land use and water management. In turn the extent and type of native vegetation Variability of water regime is a driving factor associated with wetland ecosystems is largely influencing the physical, chemical and biological dependent on wetland hydrology. Factors such components of Australian wetlands (Boulton and as width of the fringing vegetation of a wetland Brock 1999a). For example, in the Murray – Darling and its continuity, overall vegetation diversity, and Basin, some wetlands have become permanent condition all influence the quality and presence (e.g. Menindee Lakes) and act as water storages, of faunal habitat (Boulton and Brock 1999b). thus reducing variability in the water regime and The occurrence and quality of fauna habitat resulting in declines in waterbird abundance and for invertebrates, fish, frogs, reptiles and birds diversity (Kingsford et al. 2004). Other wetlands influences their distribution and breeding success are often almost permanently dry or significantly over their range. Wetland hydrology and the reduced in extent (e.g. Macquarie Marshes and the location of a wetland in its catchment contribute Lowbidgee). Largely because river regulation and to forming a unique ecosystem that provides food, water extraction have reduced flow volumes and water, critical habitat, and breeding for a range of flood frequencies, in significant declines in wetland plants and animals (Boulton and Brock 1999b). extent, vegetation and waterbirds has occurred over time (Kingsford and Thomas 1995; Kingsford and Johnson 1998; Kingsford and Thomas 2002, 2004; Kingsford and Auld 2005). Chapter 2.1 — Ecology of urban freshwater wetlands • 56

Urban Wetlands 2003). Such wetlands rely on a combination of hard engineering solutions and ecological processes to Like their rural counterparts, many urban wetlands manage nutrient loads in a catchment. In addition, have undergone substantial changes in their flow these wetlands may also provide opportunities for regimes. In particular, urban wetlands are often increased amenity and recreation in and around a subject to the adverse affects of stormwater wetland as well as refugia for local flora and fauna. runoff. Stormwater comprises of uncontrolled For example, Blue Hills Wetland in Penrith (NSW) nutrient-rich, sediment-laden wastewater. It can was developed to manage stormwater flows from lead to phytoplankton blooms in natural and the surrounding housing estate. Here Surveyors manmade systems. Such blooms promote the risk Creek, originally an intermittent system, was of eutrophication and biodiversity decline as well developed to form Blue Hills Wetland. The purpose as unsightly conditions and noxious odour. In some of the wetland was to manage adverse impacts naturally occurring wetlands that undergo seasonal associated with stormwater flows and provide flooding and drying regimes, nutrient peaks and opportunities for public recreation. The wetland phytoplankton blooms are an important part of comprises of three artificial lakes connected by a floodplain’s response to wetting (e.g. Kobayashi Surveyors Creek. The fringing and riparian zones et al. 2007). However, in an urban environment are planted with local and indigenous plant species eutrophication is often indicative of human- and provide habitat for a range of local water- induced disturbance through unnaturally high dependent fauna (Watershed Ecology 2013). A phosphorous and nitrogen concentrations (see public path skirts the wetland and storyboards Additional Information below). Indeed, wetlands highlight environmental features of the wetland. such as (ACT), phytoplankton blooms are common in the warmer months and Larger stormwater or water quality issues might represent an increased risk to public health. To be addressed through the development of more protect public health, primary contact such as extensive wetland systems. For example, the swimming and boating activities area usually Dandenong wetlands as discussed later in this cancelled (SMEC 2012). chapter, cover 48 hectares on the Dandenong Creek floodplain and are designed to reduce excessive The condition of many (remnant) natural wetlands nutrient inputs to Port Phillip Bay (Evans et al. in urban environments is challenged by flood 2010). Other naturally occurring systems, such as risks, the degree of urbanisation (sealed areas), the Edithvale – Seaford Wetlands, also filter excess deteriorating water quality and pressures on the nutrients from their catchments. The Edithvale aquatic and terrestrial habitat in and around – Seaford Wetlands are remnants of the Carrum wetlands. Indeed, the quality of stormwater is Carrum swamp, which originally stretched over typically associated with the proportion of sealed 4000 hectares (Department of Sustainability areas over a wetland’s catchment area. That is, Environment Water Populations and Communities with increasing sealed areas, such as pavements 2013). These wetlands comprise of a range of and roads, adverse water quality inputs are more permanent, intermittent freshwater and brackish likely due to increased run-off to a wetland. In many systems and filter and treat water from Boggy instances, this run-off is unlikely to have undergone Creek, Eel Race Drain and stormwater runoff before any filtration and will comprise of gross pollutants, flowing into Port Phillip Bay (Frankston City Council sediment and suspended solids, nutrients n.d.). As well as buffering the adverse effects (phosphorous and nitrogen), heavy metals, oils of human-induced disturbance, 14 ecological and surfactants (sensu) (Integrated Management vegetation classes are present and 190 bird species Information System et al. 2003). are recorded on the wetlands (Frankston City In light of increasing urban pressures, many Council n.d.). local authorities and agencies work to promote environmental outcomes for wetlands and Threats to Wetland Condition improved recreational opportunities in and around Whether urban wetlands were constructed from these waterways. A key component of this multiple pre-existing aquatic ecosystems or were naturally use approach is the rehabilitation, creation and/ occurring prior to urban development, their or recreation of wetlands (Griffith 1995). Indeed, management represents several challenges with constructed wetlands are useful in managing the respect to human activities that adversely affect quantity and quality of stormwater runoff from wetland condition. The most significant impacts impervious surfaces in their catchment (Hunter on wetland condition are changes in the seasonal Chapter 2.1 — Ecology of urban freshwater wetlands • 57

pattern of water flows over its catchment. Also of In turn, compared to wetlands in more natural importance is the diversion or extraction of water environments, the biological diversity of species from a wetland and altered run-off characteristics available to form communities, dispersal ability, (e.g. stormwater inputs) due to changes in land use and mutualistic interactions (e.g. pollination, (i.e. increasing hard surfaces) in the catchment area mycorrhizae) may all be limited or altered of a wetland. (Ehrenfeld 2000). Rare or unusual types of microhabitats, especially bush or wetland Major changes in wetland ecology include (Kleeman habitats, may be limited to non-existent in extent et al. 2008); (Ehrenfeld 2000). Both animal behaviour and plant • Changes in seasonality of flows; reproductive ecology may also be strongly affected • Reduced frequency and magnitude of floods; by the size, shape and heterogeneity of habitat patches. Thus, the possible states for the flora and • Permanent inundation or wetlands where fauna in urban areas are qualitatively different from seasonal drying and filling were natural those of non-urban areas (Ehrenfeld 2000). processes; and • Large areas of impounded water with deeper, Constructed Wetlands colder and different water chemistry. Constructed wetlands are primarily designed These hydrological changes affect profound shifts to filter stormwater by slowing water velocity, in the water chemistry and wetland flora and reducing the amount of sediment in the water fauna. Some ecological changes that occur due column and enabling natural wetland functions to to permanent inundation are (Ehrenfeld 2000; help improve the water quality. They are typically Kleeman et al. 2008); built to manage and treat stormwater before it reaches local rivers and streams and mostly urban • Replacement of species adapted to wetlands. This is because stormwater is often drying and filling by species adapted to polluted with litter and other contaminants washed permanent flooding; from roads, gardens, nature strips and gutters. • Obstruction of fish passage and some Constructed wetlands are usually situated next to water-dependent invertebrates; rivers and creeks that benefit from water quality treatment. They comprise of a shallow depression • Nutrients are often present in abundant or on the floodplain with structures that enable water over abundant amounts; and to flow in and out of the wetland with suitable • Habitat patches are often small and vegetation. A series of sedimentation ponds is isolated with connections that are difficult usually built with flow control structures that to sustain or establish. direct water into the wetland and ensure that the water is held in the wetland for a specified time Although the precise response of an urban period. Aquatic, indigenous plants, such as sedges wetland to a stressor depends on its sensitivity and rushes, are planted in the ‘fringing zone’ of the and landscape position, the general trend is a wetland and act as a carbon filter. This vegetation sharp decline in the diversity of the native plant traps plant material (for example, leaves and grass and animal community and an increase in invasive clippings) and organic matter before it enters the plant species that can tolerate stressed conditions wetland. The largest particles in the stormwater (Wright et al. 2006). Research has shown that settle on the bottom of the wetland ponds and the degraded urban wetlands lose many of their plant stems adsorb fine particles. Plant uptake and important watershed functions (Wright et al. other biological processes occurring naturally in the 2006). Upland development increases storm water water remove nitrogen from the stormwater. to wetlands, and downstream crossings create flow constrictions. Together these changes lead to Environmental Benefits from increased ponding, greater water level fluctuation, Constructed Wetlands and/or hydrologic drought in urban wetlands. In addition, urban wetlands receive greater inputs of Natural and constructed wetlands are useful in sediment, nutrients, chlorides, and other pollutants; controlling stormwater runoff generated by the concentrations in urban storm water that are impervious nature of urban development. However, typically one to two orders of magnitude greater the extent to which this can be achieved depends than predevelopment conditions (Schueler 1987). on the wetland characteristics (e.g. total wetland volume, bathymetry) and the amount of pollution Chapter 2.1 — Ecology of urban freshwater wetlands • 58

entering the wetland (loading rate) and residence The vegetated areas of wetlands are useful for time within the wetland (Hunter 2003). The main removing pollutants as they promote all three pollution removal processes include: processes (Hunter 2003). However, predicting pollutant removal is problematic and problems, • Physical: sedimentation and filtration of heavy such as eutrophication in urban systems can occur. and coarse particles; The removal rate for pathogens in natural wetlands • Chemical: breakdown of pollutants into has not been widely studied, but research on chemical compounds and elements through constructed stormwater and wastewater treatment processes such as phosphorous, nitrogen, wetlands indicates that they can be extremely carbon and sulphur cycles, redox potential effective. Constructed wetlands designed with and pH; and long retention times, high light penetration, and • Biological: the consumption of pollutants emergent vegetation achieved higher pathogen by aquatic plants and fauna that feed on removal rates than in natural wetlands (Schueler the nutrients. Associated processes include: 1999, cited in Wright et al. 2006). photosynthesis, nitrification, denitrification, While much more details and elaborate explanation and fermentation. of wetland ecology could be given here; it is perhaps a best idea to cover this aspect through diverse case study scenarios.

Additional Information 1: There are a number of closely related physico-chemical processes that influence Physico-chemical processes in a the ecology of a wetland. constructed wetland Physical processes Swapan Paul, Sydney Olympic Park Authority In a typical constructed freshwater wetland, changes in the ecology, predominantly involve: The ecological drivers that are mentioned above have consequential effects and there are several • changes in the shape and depth of the ecological processes that may occur in response. wetland and its bed; Such processes can be independent, interactive, • wetland depth and contour profile; inter-related, mutual, antagonistic, sympathetic, and/or complementary. These processes include: • water-related changes, such an quality, quantity, velocity, circulation; • Primary production, through water plants, plankton, algae and other • sediment deposition and movement plant communities of materials; • Transportation of dissolved organic • pollutants and contaminants also causing material, particulate matter, biota, etc. physical damage and interactions of wetland components; • Reproductive cues for biota such as for plant propagation, fish spawning, • light penetration related to water invertebrate breeding, plant seeding, etc. transparency, thus influencing chemical and biological activities; • Erosion and sedimentation process, involving both physical and chemical phases • etc. • Chemical processes, involving release, Particularly, water temperature directly recycling and transfer of nutrients, metals, influences aquatic life. The diversity, population minerals, etc. size, richness, fertility, mobility and health are all directly affected by changes in the water temperature of a wetland. Chapter 2.1 — Ecology of urban freshwater wetlands • 59

Chemical processes influence on nitrogen-cycle. In both stages, water pH is important. Although did Chemical processes involve many different not recommend a guideline for wetlands, elements of chemicals, whether simple to reflect urban constructed wetlands, the or complex/compound. The most familiar guidelines for freshwater lakes and reservoirs among these are the roles of nitrogen (N), is followed (ANZECC 2000) (Table 1). In phosphorus (P) and metals (sodium, potassium, freshwater wetlands, nitrogen concentrations magnesium, lead, zinc, etc.) and their cycles above 0.35 mg/L are considered undesirable. in a wetland. In this section nitrogen-cycle, The cyclic changes in nitrogen are dependent phosphorus-cycle, dissolved oxygen, pH, on the state of life-decay and nitrogen inputs. turbidity and conductivity/salinity in a As mentioned earlier, nitrogen contributes to constructed wetland are briefly described. algal growth and blooms. Nevertheless, it is Nitrogen cycle often plausible that at the peak of algal bloom the contents of nitrogen in water column is at Nitrogen plays a key role in determining the least due to the present consumption by existing flora activities in a wetland. This includes plant algae for the production of its biomass. This, growth, vigour, diversity and interactions as however, in a few days’ or weeks’ time might be well as plankton and algae. Nitrogen can come released back in the water column due to algal from soil, air and plant materials; nevertheless, decay, hence elevating the nitrogen contents the majority in urban catchments are drawn in the water column, as shown in Figure 1. in from the upper catchment/s by rain and Management decisions need to be adjusted on drain. While plants and algae/plankton are very the above bases. important components of a wetland ecosystem, excess nitrogen or an imbalance in N:P ratio Excess phosphorus can cause an imbalance in can make a pond ecologically dysfunctional or N:P ratio in water and trigger algal blooms. aesthetically unacceptable. A desirable nitrogen Phosphorus cycle to phosphorus ratio is 20:1. Phosphorus is an important component in a Bacteria and other micro-organisms play wetland system, as it is an essential requirement the major functions in transforming various for biological growth. In a freshwater system phases of Nitrogen: dissolved Ammonia (NH+ ), 4 it originates from a number of sources. Some nitrite (NO- ), nitrate (NO- ) and nitrogen gas 2 3 Phosphorous enters naturally, through the (N ), urea, amino acids and amines. Contents 2 weathering and dissolution of catchment of these various forms of Nitrogen in water soils. However, most phosphorus inputs are can provide a good indication of the dominant the result of poor land management practises. nature of the nitrogen-cycle in the water body Development activities potentially speed up at the time of water sampling. Water pH and soil erosion and sediment export process, temperature play key roles in N transformation which ultimately increases phosphorus load. as well as microorganisms and plants. For For example, sewer overflow can export high example, at pH 7, ammonium is the dominant concentration of P in the form of ammonia form of nitrogen while at pH 12, ammonia as a and faecal coliforms. Landscaping practices; dissolved gas is the dominant form. In excessive especially fertiliser run-off and industrial amounts, ammonia, in this form is considered effluent also contribute to excessive phosphorus to be a pollutant. inputs in a wetland system. The nitrification process transfers ammonia Both the dissolved and particulate forms of to nitrite in aerobic situation and the nitrite phosphorus can be found in a wetland and is converted to nitrate. Then, de-nitrification their forms can interchange with changes in occurs, converting nitrate to gaseous nitrogen. pH, temperature, dissolved oxygen and other This occurs in anaerobic environments, however, factors. A functional wetland system is truly a organic carbon (decomposed plant/animal dynamic system and the state of a chemical in materials) is required to complete this chemical a given time can only reflect or represent the reaction. Therefore, the contents of organic situation at that point in time; not necessarily matter, that is carbon in water, will have an the remaining life of the wetland. Often, such an Chapter 2.1 — Ecology of urban freshwater wetlands • 60

dissolved form or in precipitate dictates whether there could be instant flux of nutrients in the water column, or it might be locked in the sediment and gradually be released in the water column. Typically, phosphorus exits wetlands through outflow, by leaching into the subsoil, or by removal of plants and animals. Constructed wetlands, or wetlands with selective macrophytes and good root biomass (and other biofilms) can quickly adsorb phosphorus from the water column and relieve pressure on management by potentially avoiding an algal bloom, because, as discussed earlier, excess phosphorus can cause an imbalance in N: P ratio in water and quickly trigger algal blooms. Total phosphorus levels in freshwater are expected to be below 0.01 mg/L. The level of total phosphorus in a water body can be dependent on its internal sources and recycling, but in a typical urban wetland it is largely dependent on the catchment character and the degree and type of human-induced disturbance. Dissolved Oxygen (DO) Oxygen is essential for aquatic life. It enters the water column of a wetland through diffusion and aquatic plant communities also produce oxygen into the water column through photosynthesis. The oxygen so generated by water plants through photosynthetic process is Figure 1. Nitrogen and Phosphorus Cycles in a freshwater then transferred to the root zone by the plants wetland. (Source: Wetlands Ecology, workshop and made available in the sediment zone, thus notes from Wetlands.Edu, Australian Government, making the sediment oxygen rich (Brown et al. 5-6 December 2009.) 1998). In the water column, however, oxygen is generated through photosynthetic activities by important consideration is not taken into plankton/algal mass. account as part of the decision-making process Plants and animals take up oxygen during in wetland management. Monitoring of key respiration, either during the day or night. chemical parameters provide the best indication Oxygen is also consumed during decomposition, of wetland condition and an understanding nitrification and most other chemical of the underlying chemical processes that reactions. Some oxygen may be also lost in ultimately influence wetland health. Example the atmosphere. Due to respiratory activities, of relationship between phosphorus and pH especially at night when also there is almost no may be explained; as in acidic pH (below 7), photosynthetic activity, the concentration of DO phosphates of iron, aluminium and manganese in the water is generally lowest at dawn. can be highly insoluble in water and form precipitates. At pH higher than 6, calcium In constructed freshwater wetlands a healthy phosphates can form and precipitate. This DO content is expected to remain not less means that the availability of dissolved P in than 4.0 ppm and not exceed 12.0 ppm. Super water column is highly dependent on other saturation of the water column with DO can factors, including pH phosphorus availability in influence pH content and may cause tissue damage to animals in extreme situations. Fish Chapter 2.1 — Ecology of urban freshwater wetlands • 61

Table 1. Water Quality Parameter Guidelines for South-East Australia (ANZECC 2000).

ANZECC Guideline ANZECC Guideline Water Quality Parameters (Lower Limit) (Upper Limit) TP (mg/L or ppm) 0.01 - TN (mg/L or ppm) 0.35 - Ammonium (mg/l or ppm) 0.01 - DO (% saturation) 90 110 No guidelines but generally believed DO (mg/L or ppm) - to be above 4 and below 12 pH 6.5 8.0 Salinity (µS/cm) 20 30 Turbidity (NTU) 1 20 kills are often evidence of environmental stress, Turbidity either due to low dissolved oxygen or super Turbidity is a natural condition is a saturation; though the former is more prevailing. wetland, which is caused by both internal pH and external factors. Turbidity is primarily due to the suspended state of fine and/or Water pH is a measure of acidity or alkalinity coarse particles in the water column; their (sodicity) state of water. As indicated above, settlement being dependent on a number of many essential chemical reactions in a wetland factors, however, primarily due to water velocity, are dependent on its acidic or alkaline nature. depth, temperature and presence/absence of Since pH is expressed in terms of the amount of plant communities. Turbidity is a condition in H+ (Hydrogen ions) that are free to combine or a water body, which is often expressed as a bind with another negatively charged element relative measure of water clarity or muddiness or compound in the water, pH status is indeed a status. Unless it is treated or purified water, big indicator of water health. Therefore, sudden all waters in a wetland are likely to have some change in water pH is highly undesirable. degree of turbidity. This often occurs when industrial effluent is discharged or sediment-rich water released. Dead and decomposed life, natural re-suspension of sediment, movement of Water pH ranges between 0 and 14.0, with the larger creatures in the wetland can cause neutral pH being 7.0. Wetland pH is closely internal sources of turbidity. Unfortunately, associated with calcium concentrations. At pH some introduced species of fish, specifically 7.0, calcium content is 20mg/l and ideally, a carp (Cyprinus carpio), can make a wetland wetland pH should be between 6.0 and 8.0. very turbid by disturbing the bottom sediment Acidity or pH can influence most chemical through its mumbling habit. On the other reactions in a wetland, the condition and type of hand, external sources include sediment washed life forms, including fecundity, and population from lands with stormwater, pollutants and growth rates. Populations of plankton and algal particles from road-runoff and industries, mass can be also highly influenced by water pH; organic decomposed materials, etc. Among acidic pH often encourages zooplankton and these, the most common is the sediment wash alkaline pH may promote phytoplankton and from the catchment. algae. Wetland managers’ management decision is often guided by pH status. Chapter 2.1 — Ecology of urban freshwater wetlands • 62

While some turbidity is a natural phenomenon changeably, elevated saline condition in a in a wetland, too much turbidity is a problem freshwater wetland generally gives a much for aquatic life-forms in a wetland. Plant more negative connotation. communities, including plankton require light Freshwater wetlands often show high penetration for their normal functions, which levels of salinity in the water. The primary can be affected by excess turbidity. Excess reason for this phenomenon is the soils, turbidity can quickly smother submerged local geology, catchment characteristics and vegetation within days. This can trigger a series maintenance regime. of biological reactions in a wetland and quickly upset the fine ecological balance in the wetland. High salinity or conductivity readings in a Animal life can be severely affected by turbidity freshwater system indicates poor ecological in a number of ways, including loss of visual cues health. The salinity generally affects freshwater affecting feeding and breeding activities, shelter wetlands through adverse changes in the and migration, etc. It is not uncommon to electrolyte balance of plant and animal tissue/ observe mass fish kill due to excessive turbidity. cell. This can be quickly reflected in stunted The suite of flora and fauna that are likely to be growth of plant communities, hence a shift present in a wetland can be dictated by the level towards those which can tolerate higher and duration of turbidity in a wetland. salinities is favoured. Likewise, fish and other aquatic life can be directly affected by high The range of suitable turbidity in a wetland conductivity. The ultimate outcome is often a may vary depending on its usage, nevertheless, rapid shift in flora-fauna community structure in readings over 20 units (NTU) are undesirable. the wetland. Excessive turbidity can influence water chemistry in the short- and long-term. Especially, Conductivity readings vary sharply depending DO, pH and nutrient status in a wetland can vary on the type of water. These readings can be due to the level of turbidity. easily converted to salinity, which, however, requires water temperature reading as an Turbidity can be artificially (chemically) dropped important determinant. in a water body but the best approach is to let aquatic plants do the job. Emergent plants, Other Physico-chemical Cycles submerged plants, biofilms, plankton and bacteria play a key role in the natural flocculation In a constructed wetland other chemical process. The rate at which turbidity-causing reactions can occur either singly or closely linked particles flocculate/coagulate largely depends to one another. The consequences of these on the nature and size of the particles. The finer reactions on the aquatic ecosystem can be either they are in size the more likely are they to be in favorable or adverse, depending on the ongoing colloidal form and take longer to settle. Coarse catchment processes influencing wetland sand and larger particles naturally should settle condition, local climate, and goals for managing faster, however, this depends on water velocity. wetland condition. Since the ecological health of a wetland Salinity and Conductivity is largely dependent on its water chemistry Salinity being a measure of the presence of salt and the chemical nature of water can change in the water column, it is closely associated quite rapidly, it is advisable that careful with the state of electrical conductance in the considerations are given before any chemical water due to the presence of salt molecules/ treatments of wetlands. compounds. Since these two are inter- dependent, they are often measured in either form and then conversions are conducted, with temperature as an additional factor in the conversion because the electrical conductance is directly influenced by water temperature. Although in case of water quality measure, salinity and conductivity may be used inter- Chapter 2.1 — Ecology of urban freshwater wetlands • 63

Case Study 1: Dandenong the surface of the plants and assimilate fine sediments and soluble pollutants (nitrogen Wetland and phosphorous). Wetland functions are sometimes used to The Melbourne Water Waterways Alliance in improve waterway health in a catchment. Victoria (Australia) designed and constructed For some agencies, such as Melbourne Water, a 48 hectare wetland on the Dandenong constructed wetlands are considered to be Creek floodplain (Evans et al. 2010) (Figure 1). a useful method for treating stormwater on The Dandenong Wetland is in the Melbourne a regional scale as they remove pollutants suburb of Scoresby and bound by Ferntree effectively through physical, biological and Gully Road, Wellington Road, Eastlink and chemical methods (Somes et al. 2010). Dandenong Creek (Somes et al. 2010). The Stormwater wetlands are systems that are wetland was constructed with the aim of dominated by emergent macrophytes and removing excess nitrogen, phosphorous, and control stormwater run-off to remove pollutants sediment from Dandenong Creek before it before flowing into nearby rivers and streams flowed into Port Phillip Bay (Evans et al. 2010). (Melbourne Water 2010). These wetlands have To do this the Dandenong Creek Wetland was two key components: constructed with a sediment basin and a series • Sediment pond; that is, an open water inlet of interconnected wetland ‘cells’ which enable zone that reduces inflow velocity and traps water to flow through the wetland. As part coarse sediment. of the design, a calculation of the treatment capacity was conducted using estimates of • Wetland/Macrophyte Zone. Here the water flows and pollutant concentrations using wetland is shallow with extensive emergent scenario modelling (MUSIC – Model for Urban vegetation arranged in bands perpendicular Stormwater Improvement Conceptualisation). to the stormwater inflow. These plants The model, which was developed and is support a complex of algal and bacterial managed by the eWater CRC, is often used to organisms, known as biofilms, that grow on simulate urban stormwater systems at varying

Figure 1. An aerial photograph showing the construction of the Dandenong Wetlands. Eastlink is on the left, Dandenong Creek is on the right (SMEC Australia 2009). Chapter 2.1 — Ecology of urban freshwater wetlands • 64

spatial and temporal scales (Somes et al. 2010). The purpose of this modelling was to ensure that an appropriate hydrologic treatment regime is established with respect to wetland catchment area and water detention periods (Somes et al. 2010). For example, if a wetland has a specified period of 72 hours detention time then it would have a ‘wet’ hydrologic regime. That is, the wetland would experience extended periods of elevated water levels and the floral diversity would be reduced in ‘wet’ systems. Therefore it is assumed that treatment effectiveness is reduced over periods of sustained high flows as the reduction in vegetation diversity will reduce the hydraulic efficiency and interrupt treatment processes (Somes et al. 2010) The Dandenong Creek Wetland was designed to treat base and medium flows from the Dandenong Creek. This means that the water levels would be high in the wetland for extended periods when flows within Dandenong Creek were high. To reduce the impact of extended periods of high water levels, the depth of all of the wetland zones was reduced. The largest zone in the wetlands is the shallow marsh zone (Figure 2), which occupies about 45 per cent of the wetland surface. The permanent water in this zone is about 100 millimetres deep and it was possible that these areas may dry out completely during summer. The drying out of the wetland raised two issues: • The large areas of shallow or dry area would Figure 2. The marsh zone of the Dandenong Wetlands showing allow weeds to establish; or, the aquatic plantings (Peter Newall). • Plant diversity would be lost, as no habitat would remain. and faunal assemblages are likely to remain The weed issue is managed by manually limited over time. This is because the wetland manipulating water levels during the first is carefully managed to meet its environmental three years of operation, with the aim of requirements and not promote biodiversity or restricting the opportunity for weeds to form an ecosystem that contributes to broader establish (Somes et al. 2010). To provide refuges landscape processes. for plants during extended dry periods, deep pockets were introduced to create diversity to improve the wetland ecology in conjunction with breaking the visual pattern of the planting (Somes et al. 2010). Unlike naturally occurring wetlands, constructed wetlands are often designed and built to fulfil a particular aim. In this instance, the Dandenong Creek wetland was designed to remove excess nutrients and sediments from Dandenong Creek (Evans et al. 2010). As a consequence, flora Chapter 2.1 — Ecology of urban freshwater wetlands • 65

Case Study 2: Lake Tuggeranong (Percicthyidae)) or Murray cod (Maccullochella peelii (Mitchell 1839) (Percicthyidae)), for Often the key design intents of a constructed recreational fishing that also has ecological wetland can create overlapping or competing benefits (ACT Department of Environment management objectives. An example of this Climate Change Energy Water 2009). scenario is Lake Tuggeranong. Lake Tuggeranong is located in the ACT about 12.5 kilometres The Lake comprises of a large lake with three southeast of Capital Hill in . It is small weirs (SMEC 1988). One is just below surrounded by urban development, with the Drakeford Drive (that is, Isabella Pond), another Tuggeranong commercial district to the west, follows a pedestrian crossing between Anketell and significant residential development to the Street and Drakeford Drive (Figure 1) and east. The Lake was created upstream of the another, the largest weir, operates to maintain confluence between and the impoundment of Lake Tuggeranong and the by the construction includes a spillway for flows downstream into of a dam in 1987 and was filled in 1990 to Tuggeranong Creek at Athllon Drive (Figure 2). coincide with urban development in the district The two smaller weirs have full supply levels (SMEC 1988). slightly above the main lake and are designed to protect water quality (SMEC 1988). Lake Tuggeranong was developed to abate the risk of adverse impacts from stormwater inputs Stormwater to the Murrumbidgee River. The Murrumbidgee Stormwater from the Tuggeranong and River supports aquatic systems and many Erindale Town Centres flow into Lake significant natural and cultural features; Tuggeranong. For Lake Tuggeranong, water including areas of the Southern Tablelands quality inputs to Lake Tuggeranong are and the Snowy Mountains (SMEC 2012). Lake problematic (ACT Planning and Land Authority Tuggeranong was designed to provide pollution 2012). This is because the gross pollutant protection for the Murrumbidgee River, traps for stormwater in the centre remove recreational amenity and a semi-natural habitat gross pollutants but not nutrients and the feature for the town centre (SMEC 1988; Gray stormwater infrastructure does not meet 1997). The lake itself provides both riparian and current water sensitive urban design (WSUD) aquatic habitat for a range of species, and is guidelines (ACT Planning and Land Authority annually stocked with either with either golden 2012). Indeed stormwater inputs are typically perch (Macquaria ambigua (Richardson 1845) associated with degraded water quality due to high levels of nutrients and sediments. In the warmer periods, blue-green algal outbreaks can occur and pose an adverse risk to public health. As well, offensive odours are more likely which would decrease the public amenity and use of the Lake. Managing Water Quality A key challenge in the management of Lake Tuggeranong is the demand for multiple uses. That is, the demands for effective stormwater management over the catchment area of Lake Tuggeranong need to be met. Figure 1. The weir between Anketell Street and Drakeford Drive. (Photo: SMEC Yet, opportunities for recreation Australia 2011.) Chapter 2.1 — Ecology of urban freshwater wetlands • 66

in and around the lake need effective environmental solutions that maintain and improve amenity, while simultaneously abating the risk of adverse impacts from stormwater inputs to the Murrumbidgee River. To address this challenge, the management of Lake Tuggeranong seeks to provide opportunities for multiple use (sensu) (Griffith 1995). That is, address a range of objectives, such as improving water quality, enhancing aquatic and riparian habitat values, and improving recreational opportunities in and around the Lake. To address this issue in urban Figure 2. The weir exit to the Murrumbidgee River. (Photo: SMEC Australia 2011.) environments, Water Sensitive Urban Design (WSUD) measures are being considered for improving • In addition, implementing measures the water quality and subsequent stormwater to reducing pest fish species in the Lake, inputs (sensu (ACT Planning and Land Authority such as carp (Cyprinus caprio). This is 2012). Options for maintaining or improving the because reducing carp numbers can condition of urban wetlands include: significantly reduce competition with native • Reducing sediment inputs using riparian fish species for food (Gehrke et al. 2011) plantings. Where areas of the riparian zone and also improve the recreational value for are prone to erosion, native grasses for angling communities. example, can help to reduce the sediment Through careful design, wetland areas can inputs to a wetland; achieve a range of functions from improving • Increase the habitat value of a water quality to providing additional habitat wetland by incorporating the principles and increased opportunities (Griffith 1995). of urban wetland design as part of its Incorporating wetlands for effective stormwater stormwater management; treatment, such as Lake Tuggeranong, can • For Lake Tuggeranong, for example, form part of an overall strategy for improving opportunities for improving the viability of the social and environmental values of urban populations of Murray cod and golden perch wetlands. Therefore, multiple benefits can be in the Lake could be improved by increasing achieved at local and catchment levels. local habitat complexity (SMEC 2012). Through careful design, wetland areas can Examples include: achieve a range of functions from improving • Mature trees could be planted in the water quality to providing additional habitat riparian zone to provide mottled light and increased opportunities (Griffith 1995). for the Murray cod; Incorporating wetlands for effective stormwater treatment, such as Lake Tuggeranong, can • Mature wood (i.e. seasoned snags) form part of an overall strategy for improving could be placed in the Lake for silver the social and environmental values of urban perch; and, wetlands. Therefore, multiple benefits can be • Artificial habitat structures achieved at local and catchment levels. implemented as potential habitat for the Murray cod. Chapter 2.1 — Ecology of urban freshwater wetlands • 67

Case Study 3: Jerrambomberra and levee banks are visible on the surface of the floodplain. These are connected on their Wetlands western ends by a dredged channel (National The are on the Capital Development Commission 1988). Molongolo River floodplain, about four Paleochannels are uncommon in the ACT and kilometres east of Canberra Civic Centre in the are significant geomorphological features. Australian Capital Territory. They were created by The quality of water and many aspects of the construction and filling of water flow including quantity, timing, and and are in the Jerrabomberra Nature Reserve, duration are of fundamental importance to which is part of (Territory the functioning of ecosystems in this wetland. and Municipal Services 2006). The wetlands In turn, the wetland provides hydrological and comprise of permanent and ephemeral, still and water quality functions for Lake Burley Griffin. flowing waters, and their associated floodplains The flooded channels provide a permanent where the Molongolo River and Jerrabomberra drought refuge for water birds and other water- Creek enter Lake Burley Griffin. These wetlands dependent flora and fauna, as well as seasonal are unusual as they have a high biodiversity habitat for migratory bird species; particularly value in a largely artificial landscape. The reserve when Lake Bathurst and Lake George dry out in provides habitat for a large number of land and drought conditions (Department of Territory and water bird species, including migratory species Municipal Services 2010). protected under international agreements (ACT The water level in Lake Burley Griffin is normally Department of Territory and Municipal Services maintained at Australian Height Datum (AHD) 2010). Recreational uses are restricted to passive 555.93 metres by balancing inflows to the Lake or educational nature reflecting the conservation and abstraction from the Lake. The level of the focus of the Jerrabomberra Wetlands (ACT lake may fall in dry periods and during such Planning and Land Authority 2007). periods limits may apply to abstraction from The Jerrabomberra wetlands comprise of the lake (National Capital Authority 2005). old river channels that were flooded during Low flow conditions are not necessarily the filling of Lake Burley Griffin to form the detrimental to the reserve, as aquatic habitat wetlands, and pools, channels and streams. remains in , Molonglo Most of the wetland area is formed on an Reach, the Jerrabomberra Backwaters, and alluvial terrace (Dairy Flat) of the . drying out of Kellys Swamp exposes important Traces of former river channels (paleochannels) mud flat habitat. Nonetheless, the role of Jerrabomberra Wetlands as a regional ‘drought refuge’ may be reduced in these circumstances. Habitat Diversity Much of the aquatic and wetland habitat of the reserve is maintained by the relatively stable water levels through flows from Lake Burley Griffin and groundwater influences and therefore, does not experience the seasonal and episodic fluctuations in water level that are typical of many naturally occurring Australian Figure 1. The Jerrabomberra Wetlands with a bird hide in the background. (Photo: Janet Hope.) wetlands. During high Chapter 2.1 — Ecology of urban freshwater wetlands • 68

flows, water overtops the banks of the Molonglo River and Jerrabomberra Creek to enter the surrounding floodplain and create valuable ephemeral habitat. Birdlife The presence of permanent, shallow water bodies means that the wetlands are a regionally important drought refuge. In periods when Lake Bathurst and Lake George are dry, large numbers of pelicans, cormorants and coots find shelter Figure 2. The Jerrabomberra Wetlands showing bird nest boxes. (Photo: Roger Williams.) in the reserve (Figure 1 and Figure 2). One hundred and seventy bird species and maintained by the presence of a have been sighted in the reserve (Canberra large urban lake, and its vegetation cover Ornithologists Group 1987). Of these, more than of mostly introduced and planted species, 80 species of water bird species are recorded, mean that it cannot be considered from a representing most of the common water bird biodiversity perspective in the same terms species in southeastern Australia (ACT Parks and as a more naturally occurring area (ACT Conservation Service 1994). Of these, 15 to 25 Department of Territory and Municipal Services species appear to breed in the Jerrabomberra 2010). However, in relation to biodiversity Nature Reserve. Many other birds not specifically conservation, the following attributes of the associated with water habitats are also recorded reserve are significant: as occurring in the locally planted woodlands • Bioregional context: The reserve is one of a and grasslands of the reserve. The wetlands also number of wetlands in south-eastern NSW. provide habitat for up to 11 fish species as well Even though there are now well established as the eastern water rat (Hydromys chrysogaster), permanent populations of many water platypus (Ornithorhynchus anatinus) and eastern bird species on Lake Burley Griffin, water snake-necked tortoise (Chelodina longicollis). birds move between wetlands depending Significance on seasonal conditions and may migrate considerable distances. The reserve is a The Jerrabomberra Wetlands are an important ‘drought refuge’ habitat when large regional part of the vegetated wildlife corridor along the wetlands dry up and may become more Molonglo River and broader parkland system important if some wetlands are drier for of Lake Burley Griffin (Territory and Municipal longer periods due to climate change. Services 2006). An important attribute of the wetlands is the ‘drought refuge’ habitat they • Connectivity: Wetland habitats at provide when large regional wetlands such Jerrabomberra have a complementary as Lake Bathurst and Lake George dry up. As relationship with the waters of Lake noted previously, the Jerrabomberra Wetlands Burley Griffin, and the Molonglo River and is unusual in that the area has high biodiversity Jerrabomberra Creek. value in a largely artificial landscape. The small • Habitat diversity: The Jerrabomberra size of the reserve, its location amidst a range of Wetlands are characterised by: aquatic urban land uses, the wetland habitats created by and wetland habitats related to waters of Chapter 2.1 — Ecology of urban freshwater wetlands • 69

Acknowledgements Lake Burley Griffin (e.g. open water, reed The author thanks the Australian Society for bed, mudflat, and riparian vegetation); Limnology for assisting in gathering photographs exotic grasslands (Dairy Flat grazing land, for this chapter. In particular she thanks Peter marshland and wet grassland); landscape Newall, John Patten and Bob Evans. plantings (including the woodland south of Jerrabomberra Creek); and shrub cover References near Kellys Swamp. ACT Department of Environment Climate Change • The reserve contains areas of drowned Energy Water (2009). Fish stocking plan for the grassland, mudflat, shallow water, Australian Capital Territory. Environment, Canberra and marshland. These types of habitat ACT 2600. are not widespread in the ACT. In the Jerrabomberra Wetlands, these habitats ACT Department of Territory and Municipal Services vary in size or are ephemeral depending (2010). Jerrabomberra Wetlands Nature Reserve. on seasonal conditions. Plan of Management 2010. Conservation Planning and Research, Land Management and Planning • Weeds: The mainly exotic vegetation of Division, Department of Territory and Municipal the reserve contains many ACT declared Services, ACT Government, Canberra ACT 2601. weeds and other problem weed species. Despite their exotic origin, these plants ACT Parks and Conservation Service (1994). provide habitat for local fauna. Jerrabomberra Wetlands Nature Reserve Plan of Management. ACT Parks and Conservation Despite being a constructed wetland, the Service, Canberra. Jerrabomberra wetlands are locally and regionally significant. The wetlands become ACT Planning and Land Authority (2007). East drought refugia when other systems, such Lake Urban Renewal Draft Planning Report. ACT as Lake George, dry out. They also provide Government, Canberra. breeding habitat for migratory bird species ACT Planning and Land Authority (2012). protected under international agreements ideas - Tuggeranong (ACT Department of Territory and Municipal and Erindale Master Plans 2010 - 2012. Canberra Services 2010) as well as other water- ACT 2601. dependent fauna (e.g. Figure 1 and Figure 2). Nonetheless, as urbanization increases Australian New Zealand Environment and in the Jerrabomberra Creek catchment, Conservation Council the Resource Management sedimentation and the effects of high volume Council of Australia and New Zealand (ANZECC) flows may become more frequent through (2000). Australian and New Zealand Guidelines increased intensity of stormwater flows. for Fresh and Marine Water Quality: Volume 2 - Here a balance must be sought between Aquatic Ecosystems - Rationale and Background maintaining the high environmental values of Information. In ‘Australian and New Zealand the Jerrabomberra wetlands and increasing Environment and Conservation Council and the urban pressures. Resource Management Council of Australia and New Zealand’. (Ed.) Canberra ACT 2601. Boulton, A., and Brock, M. (1999a). ‘Australian Conclusions Freshwater Ecology: Processes and Management.’ (Gleneagles Publishing:South Australia.) Urban wetlands, whether constructed or natural, provide ecological services and may be of particular Boulton, A., and Brock, M. (1999b). ‘Australian importance to both people and wildlife because Freshwater Ecology: Processes and Management.’ of their location in the landscape. Management (Gleneagles Publishing: South Australia.) of urban wetlands must start with an Brown, M., Beharrel, M., and Bowling, L. (1998). understanding and assessment of the particular Chemical, Physical and Biological Process in conditions imposed by the urban environment Constructed Wetlands. The Constructed Wetlands and the goal(s) of wetland use. These conditions Manual Vol 1. NSW Department of Land and Water can be identified and incorporated into Conservation. management objectives that promote wetland function and their use in the landscape. Chapter 2.1 — Ecology of urban freshwater wetlands • 70

Canberra Ornithologists Group (1987). Avifauna of Field Guide’. (Eds G. Sainty and S. Jacobs.) the Molonglo River Corridor. Unpublished Report pp. 395–405. (Sainty and Associates Pty Ltd: Potts to the National Capital Development Commission. Point, NSW.) Canberra Ornithologists Group, Canberra. Integrated Management Information System, Coenraads, R. R., and Koivula, J. I. (2007). Masson, W. T., Sinclair, K. M., and Watson, H. (2003). ‘Geologia - The Origins of the Earth.’ (Penguin M5 South West Environmental Impacts. Prepared Books, Camberwell: Victoria.) for Interlink Roads. Department of Conservation and Environment and Kingsford, R., and Auld, K. (2005). Waterbird Office of the Environment (1992). ‘An assessment of breeding and environmental flow management Victoria’s wetlands.’ (Department of Conservation in the Macquarie Marshes, arid Australia. Rivers and Environment, Office of the Environment, Research and Applications 21, 187–200. Melbourne.) Kingsford, R., Brandis, K., Thomas, R., Crighton, P., Department of Sustainability Environment Water Knowles, E., et al. (2004). Classifying landform Populations and Communities (2013). Wetlands at broad spatial scales: the distribution and Australia. National Wetlands Update February 2013 conservation of wetlands in NSW, Australia. Marine - Issue No 22. and Freshwater Research 55, 17–31. Department of Territory and Municipal Services Kingsford, R., and Johnson, W. (1998). Impact of (2010). Jerrabomberra Wetlands Nature Reserve. water diversions on colonially nesting waterbirds in Revised Draft Plan of Management. Australian the Macquarie Marshes in arid Australia. Colonial Capital Territory, Canberra. Waterbirds 21, 159–170. Ehrenfeld, J. G. 2000. Evaluating wetlands within an Kingsford, R., and Thomas, R. (1995). The Macquarie urban context. Urban Ecosystems 4:69 - 85. Marshes and its waterbirds in arid Australia: A 50- year history of decline. Environmental Management Evans, R., Smithers, R., and Le Plastrier, B. (2010). 19, 867–878. ‘Innovative Approaches to Wetland Design at Dandenong Creek Wetland.’ (SMEC Australia Pty Ltd: Kingsford, R., and Thomas, R. (2002). Use of satellite Melbourne, VIC.) image analysis to track wetland loss on the Murrumbidgee River floodplain in arid Australia, Finlayson, C. (2000). Loss and degration of 1975-1998. Water Science and Technology 45, Australian wetlands. LAW ASIA Conference. 45–53. Environmental Law Issues in the Asia - Pacific Region. Kingsford, R., and Thomas, R. (2004). Destruction of wetlands and waterbird populations by dams Frankston City Council (n.d.). Seaford Wetlands and irrigation on the Murrumbidgee River in arid Reserve. In ‘Frankston City Council’. (Ed). Available Australia. Environmental Management 34, 383–396. at http://www.frankston.vic.gov.au/library/scripts/ objectifyMedia.aspx?file=pdf/269/91.pdf&. Kleeman, G., Epps, R., Hamper, D., Lloyd, C., Rugendyke, B., et al. (2008). ‘A Geography of Global Gehrke, P., Clarke, M., Matveev, V., St Pierre, S., and Interactions.’ (Reed International Books: Port Palmer, A. (2011). Carp control improves the health Melbourne, Victoria.) of aquatic ecosystems. Water 35, 91–95. Kobayashi, T., Shiel, R., and Segers, H. (2007). Gray, J. (1997). Statements on the Historical and First record of the rotifer Lecane shieli Segers & Cultural Background of Selected Urban Parks in Sanoamuang, 1994 from Australia. Australian Canberra - Volume 2. Canberra Urban Parks and Zoologist 34, 181–183. Places, Canberra. Melbourne Water (2010). Constructed Wetlands Griffith, E. (1995). Multiple use of urban waterways: Guidelines, Technical Report, Melbourne Water, a local government perspective of wetland ISBN 978- 921603-39-6. rehabilitation and re-creation. Wetlands (Australia) 15, 26–36. National Capital Authority (2005). Lake Burley Griffin Abstraction Plan. Commonwealth Hunter, G. (2003). Wetlands for Stormwater Government, Canberra. Management: water, vegetation and mosquitos - a recipe for concern. In ‘Waterplants in Australia. A Chapter 2.1 — Ecology of urban freshwater wetlands • 71

National Capital Development Commission (1988). Sites of Significance in the ACT. Volume 2. Inner Canberra. Technical Paper No. 56. National Capital Development Commission, Canberra. Schueler, T. (1999). Adequate Treatment Volume Critical in Virginia Stormwater Wetland. In ‘The Practice of Watershed Protection’. (Center for Watershed Protection: Ellicott City, MD.) SMEC (1988). Tuggeranong Dam Design Report Volume 1 Part 1 for the National Capital Development Commission. Cooma NSW. SMEC Australia Pty Ltd. (2012). Greenway Master Plan Aquatic Impact Assessment. Land Development Agency, 243 Northbourne Avenue, Lyneham ACT 2602. Somes, N., Bermingham, M., and Smithers, R. (2010). Dandenong Valley Wetlands an Integrated team Delivering Outstanding Environmental Outcome. Stormwater 2010 - National Conference of the Stormwater Industry Association, Star City Hotel, Sydney Australia. Territory and Municipal Services (2006). Jerrabomberra Wetlands Nature Reserve Draft Plan of Management. ACT Government, Canberra. Watershed Ecology (2013). Aquatic Ecology Monitoring Program in the Penrith Local Government Area. For Penrith City Council. Cremorne NSW 2090. Wright, T., Tomlinson, J., Schueler, T., Cappiella, K., Kitchell, A., et al. (2006). Direct and Indirect Impacts of Urbanization on Wetland Quality. Wetlands & Watersheds Article #1. Office of Wetlands, Oceans and Watersheds U.S. Environmental Protection Agency Washington, DC.